Re: [Linux-stable-mirror] [PATCH 3.16-4.4] iio: iio-trig-periodic-rtc: Free trigger resource correctly

On Wed, Nov 22, 2017 at 05:12:41PM +0000, Ben Hutchings wrote:

This is based on upstream commit 10e840dfb0b7, which did not touch the iio-trig-periodic-rtc driver because it has been removed upstream.

The following explanation comes from that commit:

These stand-alone trigger drivers were using iio_trigger_put()
where they should have been using iio_trigger_free().  The
iio_trigger_put() adds a module_put which is bad since they
never did a module_get.

In the sysfs driver, module_get/put's are used as triggers are
added & removed. This extra module_put() occurs on an error path
in the probe routine (probably rare).

In the bfin-timer & interrupt trigger drivers, the module resources
are not explicitly managed, so it's doing a put on something that
was never get'd.  It occurs on the probe error path and on the
remove path (not so rare).

Tested with the sysfs trigger driver.
The bfin & interrupt drivers were build tested & inspected only.

This was build tested only.

Cc: Alison Schofield amsfield22@gmail.com Cc: Jonathan Cameron jic23@kernel.org Signed-off-by: Ben Hutchings ben.hutchings@codethink.co.uk

Thanks for the patch, now queued up.

greg k-h